César Aquiles Lázaro

Physico-chemical and sensory attributes of low-sodium restructured caiman steaks containing microbial transglutaminase and salt replacers

Our objective was to examine the physico-chemical and sensory attributes of low-sodium restructured caiman steaks containing microbial transglutaminase (MTG) and salt replacers (KCl and MgCl2). Trimmings from caiman carcasses were processed into restructured steaks with or without MTG and salt replacers; the five treatments were CON (1.5% NaCl), T-1 (1.5% NaCl+1% MTG), T-2 (0.75% NaCl+1% MTG+0.75% KCl), T-3 (0.75% NaCl+1% MTG+0.75% MgCl2), and T-4 (0.75% NaCl+1% MTG+0.375% KCl+0.375% MgCl2). T-4 demonstrated the greatest (P<0.05) succulence and the lowest (P<0.05) values for cooked hardness, springiness, and cohesiveness. The greatest (P<0.05) purchase intention was for T-3. Furthermore, T-3 and T-4 were similar (P>0.05) to controls in salty flavor. Our findings suggest that the combination of MTG, KCl, and MgCl2 can be employed as a suitable salt reduction strategy in restructured caiman steaks without compromising sensory attributes and consumer acceptance.

Effect of high hydrostatic pressure on the color and texture parameters of refrigerated Caiman (Caiman crocodilus yacare) tail meat.

The effect of applying high hydrostatic pressure (HHP) on the instrumental parameters of color and texture and sensory characteristics of alligator meat were evaluated. Samples of alligator tail meat were sliced, vacuum-packed, pressurized and distributed into four groups: control, treated with 200 MPa/10 min, 300 MPa/10 min and 400 MPa/10 min, then stored at 4°C±1°C for 45 days. Instrumental color, texture profile and a sensory profiling using quantitative descriptive analysis were carried out on the 1st, 15th, 30th and 45th days of storage. HHP was shown to affect the color and texture of the product, and the sensory descriptors (p<0.05). The results suggest that high pressure is a promising technology for the processing of alligator meat, especially low pressures (200 MPa) which can have positive effects on the quality of the product.

Evaluation of biogenic amines levels, and biochemical and microbiological characterization of Italian-type salami sold in Rio de Janeiro, Brazil

The objective of the present study was to evaluate the levels of biogenic amines (cadaverine, putrescine, tyramine, histamine, spermidine and spermine) by high performance liquid chromatography (HPLC) and the physicochemical (moisture, lipids, proteins, pH, water activity and fixed mineral residue) and microbiological (lactic acid bacteria and aerobic heterotrophic mesophilic bacteria count) characteristics of six Italian-type salami brands sold in the city of Niteroi (Rio de Janeiro, Brazil). The salami showed lactic acid bacteria count from 5.7 to 8.6 CFU•mL-1, and heterotrophic mesophilic bacteria count from 5.8 to 8.7 CFU•mL-1. Three brands showed moisture contents above 35% and one brand had protein content below 25%. The mean values obtained for the amines were: 197.43, 143.29, 73.02, 4.52, 90.66 and 36.17 mg•kg-1 for tyramine, putrescine, cadaverine, spermidine, histamine, and spermine respectively. Two brands presented histamine contents above the legal limit established in 100 mg•kg-1. We concluded that the evaluated salami presented a wide variation in the count of the bacterial groups with a predominance of lactic acid bacteria. The moisture contents indicate insufficient drying before commercialization and protein content had values below the minimum limit determined by the Brazilian legislation. Finally, the levels of biogenic amines found could cause adverse reactions in susceptible consumers, depending of the amount and frequency of intake of these products.

Combined effect of high hydrostatic pressure and ultraviolet radiation on quality parameters of refrigerated vacuum-packed tilapia (Oreochromis niloticus) fillets

This study investigated the effects of high hydrostatic pressure (HHP) and ultraviolet radiation (UV-C), individually and combined, on the physical, chemical and bacterial parameters of Nile tilapia (Oreochromis niloticus) fillets stored at 4 °C for 14 days. Tilapia fillets were divided into four groups: control (untreated samples), UV-C, HHP, and UV-C combined with HHP (UV-C+HHP); UV-C was applied at dose of 0.103 ± 0.002 J/cm2, and HHP at a pressure of 220 MPa for 10 min at 25 °C. All samples were analyzed for total aerobic mesophilic count (TAMC), total aerobic psychrotrophic count (TAPC), Enterobacteriaceae count, pH, lipid oxidation, total volatile basic nitrogen (TVB-N), ammonia (NH3), and biogenic amines. Although UV-C accelerated (P ≤ 0.05) the formation of cadaverine, both UV-C and HHP, alone or together, retarded bacterial growth and delayed the increase (P ≤ 0.05) in pH, TVB-N, NH3 and biogenic amines during refrigerated storage, extending the shelf life of refrigerated tilapia fillets at least 2.5 times considering the TAMC counts. Lipid oxidation was unaffected (P > 0.05) by UV-C radiation, and decreased (P ≤ 0.05) by HHP and UV-C+HHP. HHP alone or combined with UV-C showed higher potential benefits for tilapia fillets preservation considering the positive influence on cadaverine levels and lipid oxidation.

Detection of Raw Milk Adulterated with Cheese Whey by Ultrasound Method

The potentiality of the ultrasound method to identify adulteration of pasteurized milk with cheese whey was evaluated. Milk samples were mixed with different concentrations of whey cheese (0, 0.5, 1, 2.5, 5, 10, 15 and 20% v/v), resulting in eight levels of adulteration (500 mL for each one). This procedure was repeated six times totaling 48 samples. Cheese whey was obtained from the manufacturing of fresh cheese under laboratory conditions. Samples were examined for conventional method and ultrasound method by lipids, cryoscopy index, density and non-fat solids. The results of fat were higher from ultrasound than conventional method. However, a significant difference between control and adulterer samples was observed by conventional method while ultrasound showed differences in samples adulterer with 5% of whey cheese onwards. For non-fat solid, only the ultrasound method showed differences in samples adulterer with 2.5% onwards. While no differences in density and cryoscopy index were shown in both methods for any level of adulteration. Although none of the methods shown to be better for the determination of adulterated milk with whey cheese, it is suggested that others physicochemical parameters will evaluate by both methods in order to find parameters indicative of adulteration in pasteurized milk adulterer with whey cheese.